The following data represents the scores of two variables, x and y: x: 10, 15, 20, 25, 30 y: 20, 25, 30, 35, 40 The correlation coefficient between x and y is:a.0.7b.0.8c.0.9d.1Clear my choice

To find the correlation coefficient between variables x and y, we can use the formula:

r = (nΣxy - ΣxΣy) / √((nΣx^2 - (Σx)^2)(nΣy^2 - (Σy)^2))

where n is the number of data points, Σxy is the sum of the products of x and y, Σx is the sum of x values, Σy is the sum of y values, Σx^2 is the sum of squared x values, and Σy^2 is the sum of squared y values.

Let's calculate the values needed for the formula:

n = 5 (since there are 5 data points) Σxy = (1020) + (1525) + (2030) + (2535) + (30*40) = 200 + 375 + 600 + 875 + 1200 = 3250 Σx = 10 + 15 + 20 + 25 + 30 = 100 Σy = 20 + 25 + 30 + 35 + 40 = 150 Σx^2 = (10^2) + (15^2) + (20^2) + (25^2) + (30^2) = 100 + 225 + 400 + 625 + 900 = 2250 Σy^2 = (20^2) + (25^2) + (30^2) + (35^2) + (40^2) = 400 + 625 + 900 + 1225 + 1600 = 4750

Now, let's substitute these values into the formula:

r = (53250 - 100150) / √((52250 - (100)^2)(54750 - (150)^2)) r = (16250 - 15000) / √((11250 - 10000)(23750 - 22500)) r = 1250 / √((1250)(1250)) r = 1250 / √(1562500) r = 1250 / 1250 r = 1

Therefore, the correlation coefficient between x and y is 1.